Booster control



Patented Nov. 26, 1946 A 1.11,]v1r1va1),y STATES PATE-Nr orgies.

Walter EgBenjamn, Anderson, Ind., assigner to Pierce Governor Company, Anderson, Ind.

Application otqbertai, 1942, seria1N0.4s3,1s9

This invention relates to a hydraulic booster of the servo-motor type, thaty is. when 'actuatedy it' multiplies the ractuatingV power tothe desired amount. f y Itis to be.k understood that servo-motors may be manually actuated. rIn conventional servomotorsf associated with governors, commonly called hydraulic, isochronous type governors, the governor weights, by reason of the parts vernployed and their connections, always are in a partlyv exploded, that is partly expanded, position when the valve of such structure responsive to such weights is in neutral. position. It is customary to compensate for this `inherent instabilityby introducing. speedfdroop by causing the power piston of the servo-motor to increase or decrease the governor main spring force..

It is the object of this invention` to eliminate this hunting or surging common to conventional servo-motorsespecially when same. are applied to such aforesaid governing structures. f n.

The chief feature of. the. present invention is the accomplishment of said objectA by utilizing a balanced valve and` `Aassociating therewith. the powerpiston so the latter merely follows the valve such that as the valve, moved either manually or by governor means, comes; to, res,t.the. ppwerlpis- 'ton also comes to rests'o that. anysurge or hunting in the system must. originate, inthe governor,

-for the power piston only duplicates valvemovement. n Y

Theadvantages of this unit' are first,z the power to move the valve lever is substantially nil, hence the governor has. extremely littleV iwork. .to do,

vmaking'it possible for a Verysrn'all governor.' to r lcontrol a lot of'useful work. Second, the use of this unit need not be confined to. governors.. For instance, two vof these units placedat righ-tangles to each other,.and'by employing afpendulum to control the valves, wouldfmake a neryjeilective',

' 3 claims. (01.121-41) low priced automatic stabilizerfor a. smallairplane.. Another useiwould beto assist. in the operation of steering very heavy trucks,that is .moving the front wheels particularly when the truck is not moving for ythen it is Valmost impgssiblegto turn the steering wheel as is wellv known,"

other use is to move'v severallevers. in conjunction with the gear shift lever ony a. vehicle. @All 'fit extends upwardly.

The full nature of the invention will be more fully understood from the accompanying drawing and the following description and'claims:

In the drawing Fig. 1 is a central sectional view of a power multiplying embodiment of the invention parts being illustrated in the idle,A- off throttle or nonpower transmitting position.

Fig. 2 is a transverse sectional view through the device approximately in the plane including the power transmitting rock-shaft.

Fig. 3 is a view similar to Fig. 1, but with the parts in the full throttle or full power transmitting'position. v

Fig. 4 is an end view of the embodiment shown in Figs. 1 to 3 and corresponding to the section shown in Fig. 2, that is 'of that end of the device.

In the drawing, IG. indicates a main body casting having an anchoring flange II. The former includes cylinder forming bore I2 enlarged at opposite ends to form chambers I3'and I4. These are closed by gaskets .and cap plates or heads I5 and i6 respectively. The se heads adjustably 'mount in apertures I'I Vand I8, respectively, the adjustable stops I9 and 21B respectively.

The flange II herein is shown provided with a pressure. uid supply passage 2| preferably, but not necessarily, connected to the engine lubricating system and to the pressure side thereof.

The body I at one end has a transverse shaft 22 and at the opposite end the master or power control shaft 23. Tc the appropriately exposed .ends of' said shafts are secured levers 24 and 25 respectively.

u By comparing Figs. 2 and 4, and same are intentionally so illustrated, observe that lever 25 Vin Fig. 2 Ais dependingly positioned, while in Fig. 4 While in Figs. 2 and 4 lever 25 is at the same end of shaft 23, note thatY the other Vend'a of the power shaft is long enough to accommodate 'lever 25 whenever it is desired to mount saine to this end.

In like manner, lever ,24 may extend upwardly from and/or maybe mounted in either position that is required in any of these several uses is to Y hook up the herein disclosed hydraulic booster to the engine oil pressure lubricating system to uti,-

lize that power instead ofthe controllingforce which as stated, may be quite small;y

' Otherobjects, features and uses lwill beset fcnthy more fullyhereinaften on the other end of shaft 22. Accordingly, both levers mayr dependA on the same side or opposite sides of. the. body, may project upwardly on the same. 4sidevor opposite sides of the body, or may, on the vsame side, have one. depend yand the other project upwardly, or the levers, as last'mentioned, maybe upon opposite sides ofthebody. universallyv adaptability to any engine and its c ontrolis provided for.

.Lever l2 4 may be manually controlled, or governor' controlled, Ythe control end leading to the accelerator, hand throttle or the governor control rod or lever as the lock lever in a centrifugal governor of conventional type.

Lever d is the main power lever and for engine control purposes it is connected to the fuel supply control of the carburetor or the like, or fuel pump rack shaft of a Diesel engine for reducing or increasing the fuel supply to the engine, and in accordance with the control imposed by the lever 2Q.

Mounted in bore l2 is power piston 25. It has a central bore 2? therethrough, which Aat the power end is threaded as at 28 to mount the member 2S provided with parallel ears 3E) that carrie-s a bridging across member 3l, the latter in the position shown in Fig. 1 contacting the adinstable stop 2o, thereby limiting clockwise movement of main power shaft 23 in the off power or initial position. Arm member 32 is adjustably secured in rock-shaft 23 as at 315 and is locked in adjusted position at 35.

When the piston 25 is pressure moved to the left from the position shown in Fig. 1 and toward the position shown in Fig. 3, cross member 3l rocks or tilts shaft 23 and lever 25 in accordance therewith. Member SI, arm 32 and shaft 23 are constrained at all times toward the position shown in Fig. l by load spring 36. This spring has one end seated about projection 31 and bears against lever 38 carrying same. Lever 38 is secured at 39 to shaft 23, see Fig. 2. An ear i8 on the body adjustably supports member lil, having projection and seat 4Z that nests in and supports the other end of load spring 36.

An arm i3 has a reduced portion Ml seated in cross bore Q5 in shaft 22. The projecting end of portion lli is annularly grooved at 45 and seats a split locking ring fil'.

In the central bore 27 of piston 26 is a valve $8. It is annularly channeled at 49. It has a central bore 'ed that communicates at one end with cross `bores 5I and is open at its opposite end adjacent member 29 which serves to seal piston bore 2l from high pressure chamber M. The channel 49 provides spaced lands 52 and 53.

The enlarged end 5s of the valve 43 is link connected as at 55 to the pilot arm 53. A light spring to the engine lubricating system sump, or may be wasted in other types of installations.

Now, when the engine fuel supply is to be reduced, from say full throttle (Fig. 3), the valve 48 is moved to the right enough to bleed off the pressure fluid in chamber I4, same reversing the flow previously described up to bore 21. However, the reduced end of the valve now forms with the bore 21 at the other end of the piston a discharge channel by which the relieved fluid wastes to `chamber I 3 for return, if desired, to the sump side the body. Herein said shaft 23, see Fig. 2, is

56 maintains a taut, but automatically adjustable connection between the valve and its operating arm, the full throttle or power position of which is limited by adjustable stop i 9 as shown in Fig. 3.

The power piston 245 is annularly grooved at El. and this groove, for all positions of said piston is in free communication with the fluid pressure supply passage 2l A cross bore 5B equalizes pressures and communicates with channel 49 in the valve for all positions of the valve and power piston.

The piston 2d includes four parallel passages ES that at one end open on the pressure face of piston 2S and each at the inner end communicates with a cross passage 66, which is sealed when land s3 close-s same and is open to pressure when bores d@ communicate with channel 4Q,

d When the latter occurs, pressure fluid is supplied to chamber I @t and becomes effective upon piston 2S to move same in opposition to spring 35 and to rotate .the power control shaft 23 in accordance with valve movement, for when the valve and piston have a corresponding position land 53 closes bores dii and the piston ceases movement. Observe that any piston-valve leakage is relieved by bore 5i?. Such leakage enters chamber I3 and is discharged as at 6| to return mounted in metal sleeve bearings 62 and locked against axial displacement by spring ring retainers 63 seating in grooves 5e in said shaft. The body shaft opening 65 is enlarged at 55 and the fluid pressure seal, including the nested intertting metal members 6l and 66 with shaft enveloping sleeve 69 and encircling spring 1G, is seated in said enlargement and prevents pressure leakage along the shaft.

It is to be observed that the spring 36, shown as a part of ystructure in Figs. 1 to 4 inclusive, may be omitted,V provided the control member (not shown) to be attached to lever 25 is itself spring loaded.

As stated, initially herein, hunting or surging, inherent in a mechanically connected servo-motor system, is eliminated. The other advantages previously mentioned are again called to attention. Furthermore, the power applied to the pilot valve has been as stated substantially negligible, while as much as twenty inch pounds of torque has been taken from the booster and applied to the carburetor valve shaft with no change whatever in engine regulation, so load and friction up to a certain point means nothing, that is, may be disregarded, wherefore no accommodation or compensation therefor need be provided.

While the invention has been illustrated and described in great detail in the drawing and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The modication'described herein as well as others `which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is: Y

1. A hydraulic booster structure including in combination a cylinder, a power piston therein and movable between the ends thereof and having a combined intake and exhaust therein terminating at the pressure end ofthe piston, a valve means controlling the combined intake and exhaust and slidably supported in said piston, a fluid pressure supply to the cylinder intermediate the ends-thereof and arranged to supply pressure to that end confronting the piston pressure face and controlled by said valve means, a discharge from theother end. ofthe cylindena dis.- charge from the piston, to the cylinder said other end, said valve means connecting said-piston discharge to the combined intake and exhaust and disconnecting same, actuating means for the valve means, and power applying means operatively connected to the power piston and operable in accordance with valve means movement, the sole power for moving said power piston toward the valvev actuating means being the pressure fluid from said supply, the actuating means including a pivoted lever, linkage between the valve means and lever and yielding means constraining said linkage and valve means toward pressure supplying position relative to the first mentioned cylinder end.

2. A hydraulic booster structure including in combination a cylinder, a power piston therein and movable between the ends thereof and having a combined intake and exhaust therein terminating at the pressure end of the piston, a valve means controlling the combined intake and exhaust and slidably supported in said piston, a fluid pressure supply to the cylinder intermediate the ends thereof and arranged to supply pressure to that end confronting the piston pressure face and controlled by said valve means, a discharge from the other end of the cylinder, a discharge from the piston to the cylinder said other end, said valve means connecting said piston discharge to the combined intake and exhaust and disconnecting same, actuating means for the valve means, and power applying means operatively connected to the power piston and operable in accordance with valve means movement, the sole power for moving said power piston toward the valve actuating means being the pressure .fluid from said supply, a load spring, means connecting the power applying means thereto for opposing power means movement in one direction of said iiuid pressure supply when communicating with the rst mentioned end of the cylinder by said valve means, said load spring moving the power means toward non-controlling position,

the actuating means including a pivoted lever, linkage between the valve means and lever and yielding means constraining said linkage and valve means toward pressure supplying position relative to the rst mentioned cylinder end.

3. A hydraulic booster structure including in combination a cylinder,l a power piston therein and movable between the ends thereof and having a combined intake and exhaust therein terminating at theA pressure end of the piston, a valve means controlling the combined intake and exhaust and slidably supported in said piston, a fluid pressure supply to the cylinder intermediate the ends thereof and arranged to supply pressure to that end confronting the piston pressure face and controlled by said Valve means, a discharge Vfrom the other end Y of the cylinder, a discharge fromV the piston to the cylinder said other end, said valve means connecting said piston discharge to the combined intake and exhaust and disconnecting same, actuating means for the valve means, and power applying means operatively connected to the power piston and operable in accordance withvalve means movement, the sole power for moving said power piston toward the valve actuating means being the pressure fluid from said supply, a load spring, means connecting the power applying means thereto for opposing power means movement in one direction of said fluid pressure supply when communicating with the first mentioned end of the cylinder by said valve means, said load spring moving the power means toward non-controlling position, and'means adjusting the force of said load spring means, the actuating means including a pivoted lever, linkage between the valve means and lever and yielding means constraining said linkage and valve means toward pressure supplying position relative tothe first mentioned cylinder end.

WALTER E. BENJAMIN. 

